Improvement in metallic piston-rod packings



CHARLES s. BARRY. Improvement in Metallic Piston-Rod Packing.

I Patented June 11,1872.

UNITED STATES PATENT QFFIOE.

CHARLES S. BARRY, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO HENRY BLUNDELL, AGENT, OF SAME PEACE.

IMPROVEMENT IN METALLIC PISTQN-ROD PACKINGS.

Specification forming part of Letters Patent No. 127,334, dated June 11,1872.

,Rod Packing.

My improvement relates to that class of segmental metallic piston-rodpacking in which the pressure of steam on the outer periphericalsurfaces of the segments induces packing contact with the rod; and itconsists in combining in one or more series several main segmentalsections, which are fitted to the rod and'nearly surround it, withslight breaks between the sections, and also several auxiliary sections,

which are located in the spaces between the ends of the main sections,and which are fitted to bear upon the rod only at such points as are notcovered by the main sections; and also in so forming the abutting endsof the main and auxiliary sections that, while force exercised on theperiphery of the main sections by the pressure of steam will induce afree inward radial'pressure against the rod, a similar force upon theperipherical surfaces of the auxiliary sections will not only induce inthem an inward radial pressure, but also cause them to force the mainsections inward against the rod with an additional degree of pressurenearly equal to that received by them direct from the pressure exercisedby the steam against their own peripheries; and I do hereby declare thatthe following specification,-

taken in connection with the drawing furnished and forming a part of thesame, is a clear, true, and exact description of a rodpacking involvingthe. several and combined features of my invention.

Referring to the drawing, Figure l represents one of my rod-packings incentral vertical section, as if in position within the gland of anupright engine. Fig. 2 represents the same in horizontal section on theline X Y, between the series of segmental sections, and exhibits theconfiguration of each section. Fig. 3 represents one of the mainsegmental sections, with the lines at the ends extended for the purposesof illustration.

A denotes the gland of the cylinder-head. B denotes the follower or cap,which is to be secured to the face of the gland by any of the well-knownmeans. 0 denotes the box or case which contains the packing. One end iscast with a flange, which extends nearly to the circumferential line ofthe rod; the other end is provided with a cover similar in character tothe flange, but provided with means for attachment to the case. Numerousports, b, are provided for the free admission of steam through the ease.D denotes one of several main segmental sections, of peculiar form. Inthis instance six of them are presented in two equal series. They may beproperly described as segmental sections of a metallic ring, having therequisite amount of metal between the inner circumference and theperiphery, and differ only from others of similar character in theirpeculiar form. Their inner curved bearing-surfaces are longer than theirouter peripherical surfaces, and their ends are jointed off on lineswhich approach each other as they advance from the inner or bearingcircumferential line. These end lines, if extended, would meet at ashort distance therefrom, and form an acute-angled or isoscelestriangle, of which the curved inner bearing or packing line wouldconstitute the base, as illustrated in Fig. 3. The length of theperipherical line of each section compares with that of the interior.

line as, say, two compares with two and threequarters, respectively; Edenotes one of several auxiliary segmental sections. They occupypositions between the ends of the main sections, and maintain, when inposition, a circumferential unity from section to section. They are soformed that they present but a small surface for contact with thepiston-rod. Their ends are jointed at such acute angles asv will causethem to correspond with the ends of the main sections. The peripheriesof these auxiliary sections are longer than the interior bearing-surface in a proportion, as shown, of, say, two and three-quarters toone-half of one. Each of the several main and auxiliary segments isprovided with an expansive spring, d, which, by hearing against theinterior of the case 0, causes the segments to be held in their properrelative position during the reaction resulting from vacuum in thecylinder, as in a condensing-engine. Each section may also be providedwith loosely-fitted dowels, enteriu g through the walls of the case, forpreventing them from turning therein. F denotes a collar, which isfitted. loosely to the inner end of the gland, and serves as a base,from which the springs G press against the inner end of the packing-caseand keep its outer end firmly against the follower. As usual in suchcases, the eye of the follower should be larger than the rod, and theinterior of the gland larger than the box which contains the packing, inorder that some slight play will be possible in case of any slight bendin the piston-rod, or or any slight undue movement other than thelongitudinal. Pressure of steam on the outer or peripherieal surfaces ofthe several main segments D freely induces them to exercise an inwardpressure on radial lines. Similar pressure on the peripherieal surfacesof the auxiliary sections E not only causes them to exert an inwardpressure against that portion of the rod with which will be compared towedges, with their smallends projecting outward from a common center,and the auxiliary section will be compared to wedges in a reversedposition, with their small ends projecting inward toward a commoncenter. Pressure applied to these latter wedges at their bases must ofnecessity not only move them inward slightly, but also move the othersinward, and with a much more rapid movement. So in practice .my segmentsare always held with proper packing relation against the rod, and socontinue as long as suflicient metal remains to constitute a practicalpacking.

In arranging two or more series of segments the joints between the mainand auxiliary segments of one series should be broken by those of thenext series in a manner well known. It will be readily observed that thejoints between the several sections are also kept closed by the pressureof steam, and that as the segments wear away next to the rod they willclose in upon it, and maintain the same practical relation to it and toeach other until worn out.

I am aware that metallic piston-rod packings have long been in use inwhich steam has been employed as the compressing agent, and that thesegments of such have been formed in many ways but I know of none priorto my invention in which main packing segmental sections were socombined with auxiliary sections that the latter not only renderedservice by assisting in packing with the rod, but also renderedimportant service in causing the main sections to operate moreefliciently by forcing them against the pistonrod.

Iclaiin as new and as my own invention- 1. The combination, within asuitable case or piston-rod stuffing-box, of the main segmental metalliesections D and the auxiliary segmental sections E, arranged in one ormore separate series, fitted so as to wholly embrace the piston-rod witha packing-surface, and jointed, one section with the other, throughouteach series, substantially as described, so that a general or specialperipherieal pressure against the segments will be utilized principallyby the main sections, whether the press ure be exercised directlyagainst them or against the auxiliary sections.

2. The combination, with a gland and an interior packing-case, providedwith ports and openings for the passage of steam from the gland into thecase, of the segmental sections D and E in one or more series andjointed, substantially as and for the purposes specified.

CHARLES S. BARRY. Witnesses:

J osnrrr W. 1\TAR'[IN, Unnnnns SELDEN.

